1990 johnson 40hp idle and reverse issues

[goddy]

hi everyone!

I purchased this outboard and boat recently and was told it just needed a carb cleaning. I've checked compression on both and is about 150 each. It wouldnt start at first but after thoroughly cleaning both carbs I've managed to get it running. It now idles only at mid to higher rpms and dies below that. I can get it into forward only if I do it extremely quickly. I've seen videos that say to try disconnecting the lower spark plug housing while the engine is running and to see how it reacts. Ive just tried today and besides shocking myself the engine remained on with no change in sound. Im extremely green with engine work and was wondering if this means its only running on 1 cylinder (high)? Would it even really make a difference if the engine was on a higher rev while I pulled it? Any insight would be awesome! Is there a way for me to post vids on here?

 

[Vic.S]

Disconnecting one spark plug at a time is the way to check if it is or is not firing on both ( all) cylinders

What you have done shows, as you realise, that it is not firing on the bottom cylinder.

First thing to try is swapping the plugs over. If its an ignition system fault it will still behave the same . If its a faulty plug It'll be disconnecting the top one which will now have no effect.

If the above shows it to be an ignition system fault then diagnostic testing , using special equipment ( at least a multi-meter with a DVA adapter ), will be necessary. Details can be found in the CDI Electronics Troubleshooting Guide but probably best left to a dealer or outboard repair workshop.

 

[goddy]

I've tried switching plugs and it still acts the same, i was playing with the screw that controls the air flow and with more air coming in ive managed to get it into reverse. Im starting to think it might just be a mixture issue or will have to go back in and see if the lower carb float is still working properly.. (maybe flooding??)I've done more research and have checked the power pack and both plug wires. The power packs clock in at 288 each. Ive replaced both plugs as well. The plug wires however need to be wiggled for constant connection and will try replacing those as well. As of right now it wont start anymore. Any other tips would be great.